Example for Configuring Local MT

This section provides an example showing how to configure local MT on IS-IS networks so that multicast packets can be transmitted on a TE tunnel.

Networking Requirements

When multicast and an Interior Gateway Protocol (IGP) Shortcut-enabled Multiprotocol Label Switching (MPLS) traffic engineering (TE) tunnel are configured on a network, the outbound interface of the route calculated by IS-IS may not be a physical interface but a TE tunnel interface. Multicast Join packets are transparent to routers through which the TE tunnel passes. Therefore, these devices cannot generate multicast forwarding entries. As a result, these devices discard received multicast packets from the multicast source.

After local MT is enabled, if the outbound interface of a calculated route is an IGP Shortcut-enabled TE tunnel interface, the routing management (RM) module creates an independent Multicast IGP (MIGP) routing table for the multicast protocol, calculates a physical outbound interface for the route, and adds the route to the MIGP routing table. Local MT resolves the conflict between multicast and a TE tunnel.

Figure 1 shows IS-IS local MT networking.

DeviceA, DeviceB, DeviceC, DeviceD, and DeviceE run IS-IS, and they are Level-2 devices.
A TE tunnel is established between DeviceB and DeviceD.
IGP Shortcut is enabled on DeviceB.

Figure 1 Local IS-IS MT networking

Device Name	Interface	IP Address
DeviceA	GE0/1/0	172.16.1.1/24
DeviceA	GE0/1/8	10.0.0.1/24
DeviceB	GE0/1/0	10.0.0.2/24
DeviceB	GE0/1/8	10.0.1.2/24
DeviceC	GE0/1/0	10.0.1.1/24
DeviceC	GE0/1/8	10.0.2.2/24
DeviceD	GE0/1/0	10.0.3.1/24
DeviceD	GE0/1/8	10.0.2.1/24
DeviceE	GE0/1/0	10.0.3.3/24
DeviceE	GE0/1/8	192.168.3.1/24

Configuration Roadmap

The configuration roadmap is as follows:

Enable basic IS-IS functions on each router.
Configure the Protocol Independent Multicast Sparse Mode (PIM-SM).
Configure an MPLS Resource Reservation Protocol (RSVP) TE tunnel and enable IGP Shortcut.
Enable local MT.

Data Preparation

To complete the configuration, you need the following data:

IP address of each router interface, as shown in Figure 1, area address 10, and originating system ID starting from 0000.0000.0001. routers are Level-2 devices.
Tunnel interface TE Tunnel 10, IP address of Loopback 0, tunnel encapsulation protocol MPLS TE, destination address 4.4.4.4, and tunnel ID 100

Procedure

Assign an IP address for each interface and enable IS-IS.
In Figure 1, assign an IP address and the mask for each interface and enable IS-IS. For configuration details, see Configuration Files in this section.

Configure PIM-SM.

# Enable multicast on all routers and enable PIM-SM on all interfaces except GE 0/1/0 on DeviceA. The configurations on DeviceB, DeviceC, DeviceD, and DeviceE are similar to those on DeviceA. For configuration details, see Configuration Files in this section.

[~DeviceA] multicast routing-enable
[*DeviceA] interface gigabitethernet 0/1/8
[*DeviceA-GigabitEthernet0/1/8] pim sm
[*DeviceA-GigabitEthernet0/1/8] commit
[~DeviceA-GigabitEthernet0/1/8] quit

# Enable IGMP on the interface through which DeviceA is connected to hosts.

[~DeviceA] interface gigabitethernet 0/1/0
[~DeviceA-GigabitEthernet0/1/0] igmp enable
[*DeviceA-GigabitEthernet0/1/0] igmp version 3
[*DeviceA-GigabitEthernet0/1/0] commit

# Configure a C-BSR and a C-RP. Set the service range of the RP on DeviceD and specify the locations of the C-BSR and the C-RP.

[~DeviceD] pim
[*DeviceD-pim] c-bsr gigabitethernet 0/1/0
[*DeviceD-pim] c-rp gigabitethernet 0/1/0
[*DeviceD-pim] commit

# Run the display multicast routing-table command to view the multicast routing table of a router. The multicast routing table on DeviceC is as follows:

[~DeviceC] display multicast routing-table
Multicast routing table of VPN-Instance: public net
 Total 1 entry
 00001. (192.168.3.2, 224.31.31.31)
       Uptime: 15:03:04
       Upstream Interface: GigabitEthernet0/1/8
       List of 1 downstream interface
           1:  GigabitEthernet0/1/0

Configure an MPLS RSVP-TE tunnel.

# Configure DeviceB.

[~DeviceB] mpls lsr-id 2.2.2.2
[*DeviceB] mpls
[*DeviceB-mpls] mpls te
[*DeviceB-mpls] mpls rsvp-te
[*DeviceB-mpls] mpls te cspf
[*DeviceB-mpls] quit
[*DeviceB] interface gigabitethernet 0/1/8
[*DeviceB-GigabitEthernet0/1/8] mpls
[*DeviceB-GigabitEthernet0/1/8] mpls te
[*DeviceB-GigabitEthernet0/1/8] mpls rsvp-te
[*DeviceB-GigabitEthernet0/1/8] quit
[*DeviceB] isis 1
[*DeviceB-isis-1] cost-style wide
[*DeviceB-isis-1] traffic-eng level-2
[*DeviceB-isis-1] commit
[~DeviceB-isis-1] quit

# Configure DeviceC.

[~DeviceC] mpls lsr-id 3.3.3.3
[*DeviceC] mpls
[*DeviceC-mpls] mpls te
[*DeviceC-mpls] mpls rsvp-te
[*DeviceC-mpls] mpls te cspf
[*DeviceC-mpls] quit
[*DeviceC] interface gigabitethernet 0/1/0
[*DeviceC-GigabitEthernet0/1/0] mpls
[*DeviceC-GigabitEthernet0/1/0] mpls te
[*DeviceC-GigabitEthernet0/1/0] mpls rsvp-te
[*DeviceC-GigabitEthernet0/1/0] quit
[*DeviceC] interface gigabitethernet 0/1/8
[*DeviceC-GigabitEthernet0/1/8] mpls
[*DeviceC-GigabitEthernet0/1/8] mpls te
[*DeviceC-GigabitEthernet0/1/8] mpls rsvp-te
[*DeviceC-GigabitEthernet0/1/8] quit
[*DeviceC] isis 1
[*DeviceC-isis-1] cost-style wide
[*DeviceC-isis-1] traffic-eng level-2
[*DeviceC-isis-1] commit
[~DeviceC-isis-1] quit

# Configure DeviceD.

[~DeviceD] mpls lsr-id 4.4.4.4
[*DeviceD] mpls
[*DeviceD-mpls] mpls te
[*DeviceD-mpls] mpls rsvp-te
[*DeviceD-mpls] mpls te cspf
[*DeviceD-mpls] quit
[*DeviceD] interface gigabitethernet 0/1/0
[*DeviceD-GigabitEthernet0/1/0] mpls
[*DeviceD-GigabitEthernet0/1/0] mpls te
[*DeviceD-GigabitEthernet0/1/0] mpls rsvp-te
[*DeviceD-GigabitEthernet0/1/0] quit
[*DeviceD] isis 1
[*DeviceD-isis-1] cost-style wide
[*DeviceD-isis-1] traffic-eng level-2
[*DeviceD-isis-1] commit
[~DeviceD-isis-1] quit

# Configure an MPLS TE tunnel and enable IGP Shortcut.

Configure an MPLS TE tunnel on DeviceB and enable IGP Shortcut.

[~DeviceB] interface Tunnel 10
[~DeviceB-Tunnel10] ip address unnumbered interface loopback 0
[*DeviceB-Tunnel10] tunnel-protocol mpls te
[*DeviceB-Tunnel10] destination 4.4.4.4
[*DeviceB-Tunnel10] mpls te tunnel-id 100
[*DeviceB-Tunnel10] mpls te igp shortcut isis
[*DeviceB-Tunnel10] mpls te igp metric relative -10
[*DeviceB-Tunnel10] isis enable 1
[*DeviceB-Tunnel10] commit
[~DeviceB-Tunnel10] quit

# Display the routing table on DeviceB. You can find that IGP Shortcut is enabled.

[~DeviceB] display isis route
                         Route information for ISIS(1)
                         -----------------------------
                        ISIS(1) Level-2 Forwarding Table
                        --------------------------------
 IPV4 Destination     IntCost    ExtCost ExitInterface   NextHop          Flags
--------------------------------------------------------------------------------
 3.3.3.3/32           10         NULL    GE0/1/8         10.0.1.1       A/-/-/-
 172.16.1.0/24        20         NULL    GE0/1/0         10.0.0.1       A/-/-/-
 2.2.2.2/32           0          NULL    Loop0           Direct         D/-/L/-
 192.168.3.0/24       25         NULL    Tun0/1/0        2.2.2.2        A/S/-/-
 5.5.5.5/32           15         NULL    Tun0/1/0        2.2.2.2        A/S/-/-
 10.0.0.0/24          10         NULL    GE0/1/0         Direct         D/-/L/-
 10.0.1.0/24          10         NULL    GE0/1/8         Direct         D/-/L/-
 4.4.4.4/32           5          NULL    Tun0/1/0        2.2.2.2        A/S/-/-
 10.0.2.0/24          15         NULL    Tun0/1/0        2.2.2.2        A/S/-/-
 10.0.3.0/24          15         NULL    Tun0/1/0        2.2.2.2        A/S/-/-
     Flags: D-Direct, A-Added to URT, L-Advertised in LSPs, S-IGP Shortcut,
                               U-Up/Down Bit Set
     Protect Type: L-Link Protect, N-Node Protect

# Display the multicast routing table on DeviceC through which the TE tunnel passes.

[~DeviceC] display multicast routing-table

No multicast routing entry is displayed, indicating that multicast packets have been discarded.

Configure local MT.

# Enable local MT on DeviceB.

[~DeviceB] isis
[~DeviceB-isis-1] local-mt enable
[*DeviceB-isis-1] commit

Verify the configuration.

# Display the multicast routing table on DeviceC again. The command output shows that multicast routes are displayed.

[~DeviceC] display multicast routing-table
Multicast routing table of VPN-Instance: public net
 Total 1 entry
 00001. (192.168.3.2, 224.31.31.31)
       Uptime: 00:00:19
       Upstream Interface: GigabitEthernet0/1/8
       List of 1 downstream interface
           1:  GigabitEthernet0/1/0

# Display the MIGP routing table on DeviceB.

[~DeviceB] display migp routing-table
Route Flags: R - relay, D - download to fib, T - to vpn-instance, B - black hole route
------------------------------------------------------------------------------
Routing Table: MIGP
         Destinations : 5        Routes : 5
Destination/Mask    Proto  Pre  Cost     Flags NextHop         Interface
      4.4.4.4/32    ISIS   15   20             10.0.1.1        GE0/1/8
      5.5.5.5/32    ISIS   15   30             10.0.1.1        GE0/1/8
     10.0.2.0/24    ISIS   15   20             10.0.1.1        GE0/1/8
     10.0.3.0/24    ISIS   15   30             10.0.1.1        GE0/1/8
  192.168.3.0/24    ISIS   15   40             10.0.1.1        GE0/1/8

The MIGP routing table shows that the original outbound interface (TE tunnel interface) has been replaced with a physical interface.

Configuration Files

DeviceA configuration file

#
 sysname DeviceA
#
 router id 1.1.1.1
#
 multicast routing-enable
#
isis 1
 is-level level-2
 cost-style wide
 network-entity 10.0000.0000.0001.00
#
interface GigabitEthernet0/1/8
 ip address 10.0.0.1 255.255.255.0
 isis enable 1
 pim sm
#
interface GigabitEthernet0/1/0
 ip address 172.16.1.1 255.255.255.0
 isis enable 1
 igmp enable
#
interface LoopBack0
 ip address 1.1.1.1 255.255.255.255
#
return

DeviceB configuration file

#
 sysname DeviceB
#
 router id 2.2.2.2
#
 multicast routing-enable
#
 mpls lsr-id 2.2.2.2
 mpls
  mpls te
  mpls rsvp-te
  mpls te cspf
#
isis 1
 is-level level-2
 cost-style wide
 network-entity 10.0000.0000.0002.00
 traffic-eng level-2
 local-mt enable
#
interface GigabitEthernet0/1/0
 ip address 10.0.0.2 255.255.255.0
 isis enable 1
 pim sm
#
interface GigabitEthernet0/1/8
 ip address 10.0.1.2 255.255.255.0
 isis enable 1
 pim sm
 mpls
 mpls te
 mpls rsvp-te
#
interface LoopBack0
 ip address 2.2.2.2 255.255.255.255
 isis enable 1
 pim sm
#
interface Tunnel10
 ip address unnumbered interface LoopBack0
 tunnel-protocol mpls te
 destination 4.4.4.4
 mpls te tunnel-id 100
 mpls te igp shortcut isis
 mpls te igp metric relative -10
 isis enable 1
 pim sm
#
pim
 C-BSR LoopBack0
 C-RP LoopBack0
#
return

DeviceC configuration file

#
 sysname DeviceC
#
 router id 3.3.3.3
#
 multicast routing-enable
#
 mpls lsr-id 3.3.3.3
 mpls
  mpls te
  mpls rsvp-te
  mpls te cspf
#
isis 1
 is-level level-2
 cost-style wide
 network-entity 10.0000.0000.0003.00
 traffic-eng level-2
#
interface GigabitEthernet0/1/0
 ip address 10.0.1.1 255.255.255.0
 isis enable 1
 pim sm
 mpls
 mpls te
 mpls rsvp-te
#
interface GigabitEthernet0/1/8
 ip address 10.0.2.2 255.255.255.0
 isis enable 1
 pim sm
 mpls
 mpls te
 mpls rsvp-te
#
interface LoopBack0
 ip address 3.3.3.3 255.255.255.255
 isis enable 1
#
return

DeviceD configuration file

#
 sysname DeviceD
#
 router id 4.4.4.4
#
 multicast routing-enable
#
 mpls lsr-id 4.4.4.4
 mpls
  mpls te
  mpls rsvp-te
  mpls te cspf
#
isis 1
 is-level level-2
 cost-style wide
 network-entity 10.0000.0000.0004.00
 traffic-eng level-2
#
interface GigabitEthernet0/1/0
 ip address 10.0.3.1 255.255.255.0
 isis enable 1
 pim sm
#
interface GigabitEthernet0/1/8
 ip address 10.0.2.1 255.255.255.0
 isis enable 1
 pim sm
 mpls
 mpls te
 mpls rsvp-te
#
interface LoopBack0
 ip address 4.4.4.4 255.255.255.255
 isis enable 1
 pim sm
#
return

DeviceE configuration file

#
 sysname DeviceE
#
 router id 5.5.5.5
#
 multicast routing-enable
#
isis 1
 is-level level-2
 cost-style wide
 network-entity 10.0000.0000.0005.00
#
interface GigabitEthernet0/1/0
 ip address 10.0.3.3 255.255.255.0
 isis enable 1
 pim sm
#
interface GigabitEthernet0/1/8
 ip address 192.168.3.1 255.255.255.0
 isis enable 1
 pim sm
#
interface LoopBack0
 ip address 5.5.5.5 255.255.255.255
 isis enable 1
 pim sm
#
return